1. Field of the Invention
The present invention generally relates to visual display panels, and more specifically to a novel and unique combination of a fluorescent dye-doped edge-illuminating emitter panel with such a visual display panel.
2. Description of the Related Art
Visual display panels such as liquid crystal displays (LCD), direct view dashboard displays, virtual image displays, aviation heads-up displays (HUD) on partial reflectors or holographs and automotive center-high-mounted stop light displays are becoming increasing popular in many applications in varied technical fields. In combination with the development of these display panels comes an increasing requirement to reduce their profile both in size and the visibility of the light source and other elements which do not form the actual display pattern. Further, it is desirable to reduce the power requirements for the display panel illumination sources.
In particular, red colored, center-high-mounted stoplight devices (CHMSL) for automotive vehicles are becoming increasingly popular due to the increased safety margin they provide. In addition to the conventional right and left mounted, red-colored rear brake lights, newer vehicles and retrofit packages for older vehicles are available which include the center-high-mounted stoplight device in the form of a third brake light which is mounted near the top of the vehicle rear window. Depression of the vehicle brake pedal causes the center-high-mounted stoplight device to be illuminated in combination with the two low mounted brake lights to form a triangle pattern with enhanced visibility and ability to attract the attention of the operator of a trailing vehicle. Experience indicates that the center-high-mounted stoplight devices have prevented traffic accidents in situations requiring emergency braking under high speed, congested traffic conditions.
Existing center-high-mounted stoplight devices generally an opaque housing with a rear-facing translucent red panel, and with an illuminating bulb inside the housing wired to the vehicle's brake circuit. The opaque housing itself constitutes a safety hazard in that it blocks a portion of the view out the rear window which the vehicle operator must see via the rear-view mirror. An opaque housing, or at least a light blocking member behind the illuminating bulb and red panel, is necessary to prevent the vehicle operator from confusing the center-high-mounted stoplight display with a light from a trailing vehicle.
Another category of display is the liquid crystal display (LCD), which has become popular in clocks and other analog and digital readout applications. These are essentially passive devices which require external illumination. Liquid crystal displays are generally transparent panels with imbedded segment or other patterns formed from a material which is normally transparent in the absence of an applied electric field, and which becomes opaque upon application of an electric field, or vice-versa. A liquid crystal display may be utilized in a transmission mode with illumination from the rear, or in a reflection mode with illumination from the front. Both modes are highly affected by ambient light which swamps the generally weak applied illumination, resulting in low visibility and contrast.